function del(tbl){
	let photo_id=tbl.photo_id
	let cnd=Cnd.where("photo_id","=",photo_id)
	let count=dao.count("cmf_app_photo",cnd)
	if(count<1){
		attr("return",{"error":201,"message":"删除失败"})
	}else{
		$update("cmf_app_photo",Chain.make("photo_status",-1),cnd)
		attr("return",{"error":200,"message":"success"})
	}
	return "json";
}